Download or read book Expression of Candidate Pierce's Disease Resistance Genes from Vitis Arizonica/candicans B43-17 in Nicotiana Tabacum Cv. Sr1 written by Carolina Bistue and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The pathogenic bacteria Xylella fastidiosa (Xf) is the causal agent of Pierce's disease (PD) in grapevines and numerous other diseases in economically important crops. Since its identification by N.B. Pierce in the 1880s there has not been an effective cure of the disease and only preventive measures have been implemented. In an attempt to find a long-term sustainable solution to PD, significant progress in the classical breeding of PD resistant plants has been made. The goal has been to obtain grapevines with resistance to PD from native American Vitis species while conserving as much quality from elite Vitis vinifera wine, table and raisin grapes. The genetic mapping of Vitis arizonica/candicans b43-17, used as a resistance source by the University of California, Davis breeding program, resulted in the localization of a homozygous dominant locus, designated PdR1, responsible for PD resistance. Physical mapping and sequence analysis around this locus resulted in the identification of five candidate genes denominated PdR1b.1, PdR1b.2, PdR1b.3, PdR1b.4 and PdR1b.5. In order to fully characterize them, as a first step to understand their function, we have conducted complementation assays using transformation of tobacco via Agrobacterium tumefaciens. In this study, plants of Nicotiana tabacum cv. SR1 were transformed and screened for PD resistance under greenhouse conditions. Tobacco plants transformed with genes PdR1b.1 and PdR1b.5 exhibited significantly less symptoms than the control untransformed plants. Transformations were also conducted on three susceptible Vitis cultivars and screenings are underway. The understanding of these genes could further assist in the efforts of finding long-term solutions for the disease.